A new route for difficult-to-recycle packaging

Researchers from the University of California, Los Angeles (UCLA) Samueli School of Engineering and Ewha Womans University have developed a process capable of converting mixed plastic packaging waste into high-purity hydrogen while capturing much of the carbon in stable solid compounds. The approach offers a promising alternative for packaging materials that are difficult or uneconomical to recycle through conventional mechanical methods.

The technology, known as alkaline thermal treatment (ATT), processes multiple plastic types—including PET, polyethylene (PE) and polypropylene (PP)—within a single reactor. Unlike traditional recycling systems that require plastics to be carefully sorted before processing, ATT is designed to handle heterogeneous packaging waste, significantly simplifying the treatment process.

Addressing one of recycling's biggest challenges

Mixed packaging waste remains one of the most significant obstacles to achieving higher recycling rates. Multilayer structures, labels, adhesives, printing inks and food contamination often make mechanical recycling technically challenging and economically unattractive. As a result, large volumes of packaging are still sent for incineration or landfill.

The newly developed process aims to recover value from these residual waste streams by transforming them into a useful industrial resource. Because several plastic materials can be treated together, the need for extensive sorting is greatly reduced, making the technology particularly attractive for post-consumer packaging that would otherwise have little recycling value.

Producing hydrogen while reducing emissions

During the ATT process, sodium hydroxide reacts with plastic materials under controlled heat, generating hydrogen with reported purities exceeding 90%. At the same time, a significant proportion of the carbon contained within the plastics is captured as stable sodium carbonate rather than being released as carbon dioxide.

This dual benefit differentiates the technology from conventional waste incineration, where most of the carbon contained in plastic packaging is emitted directly into the atmosphere. By combining hydrogen production with carbon capture, the process could contribute to lower greenhouse gas emissions while creating an additional source of clean energy.

Complementing mechanical recycling

The researchers emphasise that ATT is not intended to replace established recycling methods. Instead, it is designed to complement mechanical recycling by focusing on packaging fractions that cannot be economically recycled through existing infrastructure.

High-quality, single-polymer packaging should continue to follow conventional recycling routes whenever possible, while contaminated and mixed materials could be diverted to hydrogen production. This integrated approach could improve overall resource recovery and reduce dependence on landfill and incineration, supporting circular economy objectives without disrupting current recycling systems.

Challenges remain before commercial deployment

Although the technology has demonstrated promising laboratory results, further development is required before industrial implementation. Future work will focus on improving reactor efficiency, recovering and reusing sodium hydroxide, validating continuous processing with real packaging waste streams and evaluating commercial-scale economics.

If successfully scaled, alkaline thermal treatment could provide the packaging industry with an additional solution for managing complex plastic waste while simultaneously producing clean hydrogen. As governments and manufacturers seek new pathways to reduce carbon emissions and improve resource efficiency, technologies capable of converting difficult-to-recycle packaging into valuable energy carriers may become an increasingly important part of future circular packaging systems.